reverted canvas version

yeah it ain't building

Author: fluxehub

package.json

@@ -92,7 +92,7 @@
     "babel-jest": "23.6.0",
     "babel-loader": "8.0.4",
     "babel-plugin-lodash": "3.3.4",
-    "canvas": "^2.6.0",
+    "canvas": "^1.6.12",
     "cross-env": "^5.2.0",
     "css-loader": "^1.0.1",
     "enzyme": "3.7.0",